CORE C: Protein Chemistry Core The Protein Chemistry Core will continue to provide for the research groups in the Program Project the technical expertise and equipment required for the isolation and sequence analysis of receptor fragments containing the sites of photoincorporation by general anesthetics. In addition, the Core provides computational resources for the molecular modeling that is necessary to interpret the protein chemistry results in terms of models of receptor structure and to provide guidance in the design of mutational analyses necessary to define the energetic contributions to anesthetic binding. The Core is under the supervision of Dr. Cohen and is located in his laboratory. Major equipment cunrently available in the Core include (i) an Applied Biosystems 492 Precise automated Protein Sequenator and in-line amino acid analyzer;and (ii) 2 Agilent 1100 HPLCs equipped with UV and fluorescence detectors;and (iii) an Agilent 1100 capillary LC system. The biochemical characterization of anesthetic binding sites in ligand-gated ion channels requires the use of highly specialized techniques not normally available in protein chemistry core facilities which usually do not accept radioactive samples either for Edman degradation or mass spectrometry. The identification of drug binding sites within the hydrophobic domains of integral membrane proteins poses unique problems for peptide isolation and characterization by either Edman degradation or mass spectrometry. It is the function of the Core to provide the appropriate equipment and highly skilled protein chemists who can interact directly with the research projects to develop and carry out the appropriate research strategies and to educate the investigators about the necessary protein chemistry techniques to be carried out either in the Core or in the investigator's lab. RELEVANCE (See instructions): GABAARS in the brain are a major site of action of many clinically used anesthetics of diverse chemical structure, but the number and location of anesthetic binding sites within GABAARS or in the structurally related nicotinic acetylcholine and serotonin 5-HT3 receptors remains unknown. This Core provides the resources necessary to identify these binding sites.